Best Method/Material for Motor potting

propulsion

#1

I have brushless motors for my homemade ROV, (Motor Link Here) and I have heard they run fine underwater, but dirt and paricles in the water may damage them, and that coating them in epoxy (or some other waterproof material) would protect them. I was wondering what is the best way to waterproof these motors and what would be the best material for it?